A team of scientists fromUniversity of Chinese Academy of Sciences developed an ultra-thin perovskite solar cell, integrating a resonator Gires-Tournois to revolutionize the absorption of light. This approach could not only improve energy efficiency, but also reduce costs and the environmental impact linked to the materials used.
The secret of the design: Gires-Tournois resonators
Gires-Tournois resonators, advanced optical devices designed to create standing waves and chromatic dispersions, have found a new application in solar cells. Often used for the compression of optical pulses, these instruments have been integrated into a simple but ingenious configuration, as explained by the scientists themselves:
We chose to combine a silver rear mirror with an equally simple optical structure. This design optimizes light capture and absorption, greatly improving its overall efficiency.
The team’s work focused on the choice of materials and the precise definition of the thickness of each layer. We conducted a series of simulations to select silver as the ideal material for the reflective mirror.
The cell structure presents a highly sophisticated stratification:
This configuration demonstrated an average light absorption of 85%, with a significant increase in the wavelength range between 400 and 800 nm. This increase is made possible thanks to the interference effects between the perovskite layer and the metal backlayer.
Optical simulations and tests conducted with SCAPS software demonstrate that this ultra-thin cell can achieve a photoelectric conversion efficiency of 26%,” says Dai. “Under optimal conditions, efficiency could reach 27%.
In addition to exceptional efficiency, the design introduces significant environmental benefits. By using an ultra-thin layer of perovskite, material consumption is drastically reduced, reducing costs and the amount of lead used in the device, as highlighted by the researchers:
Using such a thin absorber layer significantly reduces material costs and decreases the lead content in the device, which is crucial for improving sustainability.
However, to replicate this performance on a commercial scale, it will be necessary to adopt advanced techniques such as vacuum deposition. The study, entitled “Ultrathin perovskite solar cell based on Gires-Tournois resonator configuration with 27% theoretical efficiency”, was recently published in the scientific journal Solar Energy.
